In the rich text editor:
@Enwy
In a comment:
[Enwy](https://chowlings.com/user/Enwy)
For Names and Avatars:
In the rich text editor:
%Enwy
In a comment:
[![Enwy's Avatar](https://chowlings.com/images/avatars/default.jpg)](https://chowlings.com/user/Enwy) [Enwy](https://chowlings.com/user/Enwy)